1. Field of the Invention
The present invention relates to a liquid crystal display device and a projector, and more particularly to a liquid crystal display device which uses a reflective liquid crystal display panel and a projector.
2. Description of the Related Art
As a liquid crystal display device used for a projector, there has been known a reflective liquid crystal display device (see JP-A-2003-271108 (liquid crystal display device)).
As one of the reflective liquid crystal display devices, there has been known a liquid crystal display device which adopts an electrically controlled birefringence mode.
FIG. 6 is a view for explaining a single polarizer twisted nematic mode (SPTN) which is one of the electrically controlled birefringence modes.
As shown in the drawing, an incident light L1 from a light source (not shown in the drawing) is divided into two polarized lights by a polarization beam splitter 15 and light L2 which is constituted of a linearly polarized light is radiated.
As shown in FIG. 6A, when a voltage is not applied to liquid crystal, the light which is incident on a liquid crystal panel 100 becomes an elliptically polarized light due to the birefringence of a liquid crystal composition 3 and becomes a circularly polarized light on a reflection electrode 5. The light which is reflected on the reflection electrode 5 passes through the liquid crystal composition 3 again and becomes the elliptically polarized light, and returns to the linearly polarized light at the time of irradiation, and is radiated as a light L3 (S polarized wave) which has a phase thereof rotated by 90 degrees with respect to the incident light L2. Although the radiation light L3 is incident on the polarized beam splitter 15 again, the radiation light L3 is reflected on a polarization surface and becomes an irradiation light L4. This irradiation light L4 is radiated to a screen or the like for performing a display.
The above constitutes a display method which is referred to as a so-called normally white (normally open) in which the light is radiated when the voltage is not applied to the liquid crystal.
To the contrary, as shown in FIG. 6B, when the voltage is applied to the liquid crystal composition 3, liquid crystal molecules are aligned in the direction of an electric field and hence, a rate that the birefringence is generated in the inside of the liquid crystal is reduced. Accordingly, the light L2 which is incident on the liquid crystal panel 100 as the linearly polarized light is directly reflected on the reflection electrode 5 as it is, and is radiated as a light L5 having the same polarization direction as the incident light L2. The radiated light L5 passes through the polarization beam splitter 15 and returns to the light source. Accordingly, the light is not radiated to the screen or the like thus performing a black display,